This is probably the world's tastiest QR code ever! To celebrate New
Year, Chinese Internet company Tencent commissioned a giant cake shaped
like a QR code and served it to 20,000 people:

The cake, which takes up a floor area of 36 square meters and weighs
three tons, was produced by Tencent, an Internet and smartphone value-added
service provider, and Ebeecake, a local bakery. It took ten hours to
finish the QR code pattern on the cake's surface. By scanning the QR
code pattern, smartphone users can download and install Tencent's news
service client onto their gears.